Add support for determining the public facing IP address via UPNP by querying the user's router.
I will attempt to work this out on my own and submit the code if I get it to work.
Sample Perl script to get external IP via UPnP
After reviewing the available Perl modules and the make up of the ddclient code, I don't believe that this would be a good fit for directly implementing in the ddclient code. It would add a dependency on external non-standard modules that it doesn't need.
That said, I have attached a sample script that can be used by using use=cmd in the ddclient configuration file or being passed via the -cmd= option.
It's a crude first stab, but seems to work well for me.